[INFO] updating cached repository nakakura/tokio_udp_sendrecv_example
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/nakakura/tokio_udp_sendrecv_example
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/nakakura/tokio_udp_sendrecv_example" "work/ex/beta-1.38-1/sources/1.37.0/gh/nakakura/tokio_udp_sendrecv_example"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/nakakura/tokio_udp_sendrecv_example'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/nakakura/tokio_udp_sendrecv_example" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nakakura/tokio_udp_sendrecv_example"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nakakura/tokio_udp_sendrecv_example'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8a2d2acc59bb69de09d4bbf7552f535d131c016c
[INFO] sha for GitHub repo nakakura/tokio_udp_sendrecv_example: 8a2d2acc59bb69de09d4bbf7552f535d131c016c
[INFO] validating manifest of nakakura/tokio_udp_sendrecv_example on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of nakakura/tokio_udp_sendrecv_example on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing nakakura/tokio_udp_sendrecv_example
[INFO] finished frobbing nakakura/tokio_udp_sendrecv_example
[INFO] frobbed toml for nakakura/tokio_udp_sendrecv_example written to work/ex/beta-1.38-1/sources/1.37.0/gh/nakakura/tokio_udp_sendrecv_example/Cargo.toml
[INFO] started frobbing nakakura/tokio_udp_sendrecv_example
[INFO] finished frobbing nakakura/tokio_udp_sendrecv_example
[INFO] frobbed toml for nakakura/tokio_udp_sendrecv_example written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nakakura/tokio_udp_sendrecv_example/Cargo.toml
[INFO] crate nakakura/tokio_udp_sendrecv_example already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing nakakura/tokio_udp_sendrecv_example against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nakakura/tokio_udp_sendrecv_example:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 018315630b5f9e27b95c6cd5608c478aba9ef601ab16589bc4b0172c099cc7be
[INFO] running `"docker" "start" "-a" "018315630b5f9e27b95c6cd5608c478aba9ef601ab16589bc4b0172c099cc7be"`
[INFO] [stderr]    Compiling net2 v0.2.32
[INFO] [stderr]    Compiling crossbeam-epoch v0.4.1
[INFO] [stderr]    Compiling bytes v0.4.7
[INFO] [stderr]    Compiling mio v0.6.14
[INFO] [stderr]    Compiling crossbeam-deque v0.3.1
[INFO] [stderr]    Compiling tokio-io v0.1.6
[INFO] [stderr]    Compiling tokio-threadpool v0.1.3
[INFO] [stderr]    Compiling tokio-reactor v0.1.1
[INFO] [stderr]    Compiling tokio-fs v0.1.0
[INFO] [stderr]    Compiling tokio-udp v0.1.0
[INFO] [stderr]    Compiling tokio-tcp v0.1.0
[INFO] [stderr]    Compiling tokio v0.1.6
[INFO] [stderr]    Compiling udp_sendrecv_tokio v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(drain_filter)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `udp_sendrecv_tokio`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "018315630b5f9e27b95c6cd5608c478aba9ef601ab16589bc4b0172c099cc7be"`
[INFO] running `"docker" "rm" "-f" "018315630b5f9e27b95c6cd5608c478aba9ef601ab16589bc4b0172c099cc7be"`
[INFO] [stdout] 018315630b5f9e27b95c6cd5608c478aba9ef601ab16589bc4b0172c099cc7be